add auto-close destructor and test

Author: scivision

VERSION

@@ -1 +1 @@
-1.3.0
+1.3.1

src/interface.f90

@@ -64,6 +64,9 @@ module nc4fortran
   nc_read_scalar, nc_read_1d, nc_read_2d, nc_read_3d, nc_read_4d, nc_read_5d, nc_read_6d, nc_read_7d, &
   def_dims
 
+!> flush file to disk and close file if user forgets to do so.
+final :: destructor
+
 end type netcdf_file
 
 !> Submodules
@@ -539,6 +542,18 @@ subroutine nc_initialize(self,filename,ierr, status,action,comp_lvl,verbose,debu
 end subroutine nc_initialize
 
 
+subroutine destructor(self)
+!! Close file and handle if user forgets to do so
+
+type(netcdf_file), intent(inout) :: self
+
+print *, "auto-closing " // self%filename
+
+call self%close()
+
+end subroutine destructor
+
+
 subroutine nc_finalize(self, ierr)
 class(netcdf_file), intent(inout) :: self
 integer, intent(out), optional :: ierr

src/tests/CMakeLists.txt

@@ -7,7 +7,7 @@ set_tests_properties(nc4fortran:minimal PROPERTIES
   FIXTURES_SETUP nclib
   LABELS core)
 
-foreach(t array attributes deflate error exist scalar shape string)
+foreach(t array attributes deflate destructor error exist scalar shape string)
   add_executable(test_${t} test_${t}.f90)
   target_link_libraries(test_${t} PRIVATE nc4fortran::nc4fortran)
   set_target_properties(test_${t} PROPERTIES LABELS unit)

src/tests/meson.build

@@ -6,7 +6,7 @@ test('minimal', test_minimal,
   priority: 100,
   timeout: 10)
 
-foreach t : ['array', 'attributes', 'deflate', 'error', 'exist', 'scalar', 'shape', 'string']
+foreach t : ['array', 'attributes', 'deflate', 'destructor', 'error', 'exist', 'scalar', 'shape', 'string']
 
   e = executable('test_'+t, 'test_' + t + '.f90', dependencies: netcdf_interface, fortran_args: quiet)
   if t == 'shape'

src/tests/test_destructor.f90

@@ -0,0 +1,35 @@
+program test_destruct
+!! test netcdf_file destructor, that should auto-flush and close file
+!! if user forgets to %close() file
+
+use, intrinsic :: iso_fortran_env, only : stderr=>error_unit
+use nc4fortran, only: netcdf_file
+implicit none (type, external)
+
+call test_destructor()
+print *, 'OK: destructor'
+
+contains
+
+
+subroutine test_destructor()
+type(netcdf_file) :: h
+character(*), parameter :: fn = 'destructor.nc'
+integer :: i
+
+block
+  type(netcdf_file) :: h
+  !! we use block to test destructor is invoked
+  call h%open(fn, action="write", status="replace")
+  call h%write('x', 42)
+end block
+
+if(h%is_open) error stop "destructor did not close " // fn
+
+call h%open(fn, action="read", status="old")
+call h%read("x", i)
+if(i/=42) error stop "destructor did not flush " // fn
+
+end subroutine test_destructor
+
+end program